Screen for projecting.



L. GAUMONT.

SCREEN FOR PROJECTING.

APPLlCATl0N FlLED mac. 29. 1913.

Patented July 3, 1917.

WITNESSE S; f 'w INVENTOR By Atto rneys, 6km QM 5 main eras rannrclarion.

LEON GAUMONT, 0F PARIS, FRANCE, ASSIGNOR TO SOCIETE DES ETABLISSEMENTSGAUMONT, OF PARIS, FRANCE.

SCREEN FOB, PROJECTING.

Specification of Letters Patent.-

Patented July 3, 11917.

Application filed December 29, 1913. Serial No. 809,405.

To all whom it may concern:

Be it known that I, L120: GAUMONT, a citizen of the Republic of France,residing in Paris, France, have invented certain new and usefulImprovements 'in Screens for Projecting, of which the following is aspecification.

This application relates to transparent screens used for projecting.

Linen-cloth, calico and like material have hitherto been used for thispurpose, being made transparent by keeping them moist with water, towhich a certain proportion of glycerin is usually added, or else byapplying a varnish, or a gelatin coating.

The applicant has contrived a screen for projecting by transparency andpossessed with a powerful luminous efiect by using tulle i. e. a fabricin which the opaque part is very small as compared with the spaces orempty part. A thin layer of a translucent material is applied to thistulle, such as a solution of gelatin for instance, in which apulverulent substance held in suspension,

such a baryta, talc and the like is incorpo rated, in short an emulsion,or the emulsion may be of opalescent material such as starch paste orsome other paste, and finally a second coating of varnish may be givento the tulle, so as to impart such a transparency to the whole devicethat the projected view is withheld or checked, although the deviceretains its luminosity completely. After drying the translucent surfacecould also be frosted by means of a sand blast or any other process.

Figure 1 of the accompanying drawings shows a fragment of the screen ona magni fied scale, Fig. 2 being a transverse section thereof.

In the drawings, a a are the threads, wires, or other filamentsconstitut ng the open-mesh fabric, and b is the filling of gelatinorother translucent or nearly transparent substance in which is held thenontransparent material which 'ives the translucent effect to thescreen, belng here shown as particles 0 0 of a pulverulent substance, orwhich may be taken as cells of starch or the like.

It is obvious that instead of tulle another open fabric or a wire gauzecould for instance be used and that the gelatin solution could bereplaced by collodion or some other material that is able to form a verythin and very transparent surface on being dried.

The gelatin or other emulsion or cementitious body may be renderedinsoluble by means of formol, bichromate of potash, etc.

What I claim is: 1. translucent screen for projecting, comprlsing afabric of filaments, so sepa rated that the opaque area is smallcompared with the area of the intervening spaces, with a translucentcementitious substance fillingits interstices, a hardening agent forsuch cementitious substance, and a non-transparent material held in anddistributed through such cementitious substance.

- 2. A translucent screen for projecting, comprising a fabric offilaments so scparated that the opaque area is small compared with thearea of the intervening spaces, with a translucent gelatinouscementitious substance filling its interstices, a hardening agentrendering such gelatinous substance insoluble, and a subdividednontransparent material held in and distributed through such gelatinous.substance.

In witness whereof, I have hereunto signed my name in the presence oftwo subscribing witnesses.

LEON GAUMONT. Witnesses Humor: 0. Coxn, GABRIEL BELLIARD.

